Ras-related protein Rab-13

RAB13 is a small GTPase that regulates intracellular membrane trafficking by cycling between inactive GDP-bound and active GTP-bound states to recruit downstream effectors (UniProt: P51153). It controls endocytic recycling and transport of transmembrane proteins to the plasma membrane, thereby regulating tight junction assembly and activity. RAB13 also participates in actin cytoskeleton reorganization, angiogenesis, neurite outgrowth, and glucose homeostasis through GLUT4 trafficking (UniProt: P51153).

In Alzheimer's Disease, RAB13 is consistently upregulated in post-mortem human AD brain tissue compared to age-matched controls (Chaparral AD proteomics). The protein shows a mean log2 fold-change of 0.64 across quantified subcellular fractions from TMT-labeled differential proteomics analysis of four fractions (P2, P3, S2, S3). This upregulation may reflect altered membrane trafficking dynamics and vesicular transport dysfunction characteristic of AD pathology, though the functional consequences remain to be elucidated.